Erosion is a common problem along waterways including ocean shores, river beds, lake shores, etc. This is particularly true for shores with poor load bearing soils, such as soils with high organic content, as long term settlement lowers the utility of current retaining walls and shoreline protection systems.
Current approaches for erosion control include earth retaining walls, heavy systems with large pile foundation support, and floating breakwater systems. Earthen retaining walls are subject to considerable erosion and typically settle readily and therefore require high frequency maintenance.
The materials to build earthen retaining walls are relatively inexpensive, but the high frequency maintenance increases costs considerably. Heavy systems with large pile foundation support are greatly protected from settlement, but the cost of driving large piles deep enough and the cost of the heavy systems have a very high initial cost. Floating breakwater systems do not provide as much erosion control as other approaches as they transfer some wave action and also allow currents and water flow underneath the system, in turn allowing erosion of shoreline and off-shore soils, sand, and supporting ground generally.